In order to create a map using the pseudo-testcross approach, the
data needs to be split into parent specific subsets. This function
uses the segregation type to create subset given an input object
of type group.
pseudo.testcross.split(input.obj)an object of class group
A list with two marker sequences for each linkage group. One for sequences with type "D2.15", one for those with type "D1.10".